System for actuating a two part mould forming two mutually articulated half-moulds

Abstract

The invention concerns a system for actuating a two-part mould (1) forming two half-moulds (1, 1) mutually articulated about a shaft (2) forming a hinge and driven, between an opening position and a closing position, by a translational carriage (7) driven in a reciprocating movement. The inventive system is particularly characterised in that each half-mould (1, 1) is further articulated on a part (4a, 4b) which pivots about a shaft (5a, 5b) and which is driven in rotation by at least an actuating link rod (6a, 6b) articulated through its ends respectively to said pivoting part (4a, 4b) and to said translational carriage (7).

Description

[0001] The invention relates to an actuation system for a mould in two parts forming two half-moulds articulated about an axis forming a hinge.

[0002] It is known how to make moulds in two parts or half-moulds, particularly for injection moulding and blowing moulding machines.

[0003] Each of the two half-moulds is usually mounted on a carriage, and they are moved towards each other while remaining parallel to each other.

[0004] Systems in which the two-half moulds are articulated about an axis forming a hinge and controlled between an open position and a closed position by a trolley free to move in translation in a forward-backward movement, as described in French patent 2 059 446 and 2 088 523 and in application FR-2 793 722, have also been known for a long time.

[0005] The invention relates to a system for the actuation of a two-part mould forming two-half moulds of the type mentioned above, but which is remarkable in that each half-mould is also articulated on a part that pivots about an axis and that is moved in rotation by at least one actuation rod articulated by its ends to the said pivoting part and to the said carriage free to move in translation respectively.

[0006] According to one embodiment, each half-mould is articulated on the pivoting part by at least one connecting rod, whereas the actuation rods for the pivoting parts of the half-moulds are articulated on a common translation carriage, and more particularly in the latter case, the translation carriage is for example composed of a cross piece that is installed free to slide on at least two rails and on which the actuation connecting rods are articulated.

[0007] Preferably, the translation carriage is moved forwards and backwards by at least one roller that cooperates with a cam and, for example, the roller may be placed on a connecting rod installed so as to pivot about an axis fixed with respect to the pivoting axes of the pivoting parts activating the half-mould.

[0008] Advantageously, when the half-moulds are in the closed position, the longitudinal axes of the connecting rods installed between the said half-moulds and the pivoting parts are approximately in line with each other along the line joining the pivoting axes of the said pivoting parts.

[0009] Due to this arrangement, the half-moulds are naturally locked to each other when in the closed position without any other complementary means.

[0010] The invention also relates to a set of moulds each provided with an actuation system like that mentioned above, this assembly being remarkable in that the moulds are arranged in a circle or along the arc of a circle and in that the translation carriages are moved by rollers that cooperate with a common cam, the said moulds moving relative to the cam.

[0011] According to one embodiment, the moulds are fixed on an element that rotates about the common cam that is fixed in position, but it could also be imagined that the moulds could be fixed and the cam could be moved in a rotary movement.

[0012] The invention will be better understood after reading the following description with reference to the attached drawings in which:

[0013] FIGS. 1 and 2 show a perspective view of a system according to the invention, the mould being shown in the open and closed positions respectively;

[0014] FIGS. 3 and 4 show a top view of the systems in FIGS. 1 and 2 respectively, also partly showing the actuation cam;

[0015] FIG. 5 is a top view of a set of several moulds each provided with an actuation system controlled by a common cam.

[0016] As shown on the drawings, the system according to the invention will actuate a mould 1 in two parts forming two half-moulds 1′, 1″ articulated to each other about an axis 2 forming a hinge.

[0017] Each half-mould 1′, 1″ is articulated through a connecting rod 3a, 3b on a part 4a, 4b that is installed free to pivot about an axis 5a, 5b.

[0018] The pivoting parts 4a, 4b are each moved in rotation by an actuation rod 6a, 6b articulated by its ends to the said part 4a, 4b respectively and to a translation carriage 7.

[0019] The carriage 7 consists of a cross piece that is installed free to slide on two rails 8a, 8b, and on which one of the ends of the actuation rods 6a, 6b is articulated.

[0020] In this way, it can be understood that with a forward-backward movement of the carriage 7, the assembly moves from the open position in FIGS. 1 and 3 to the corresponding closed position in FIGS. 2 and 4 and vice versa.

[0021] Translation of the carriage 7 causes pivoting of parts 4a, 4b, by means of the connecting rods 6a, 6b, and thus closes and then opens the moulds through the action of the connecting rods 3a, 3b on the half-moulds 1′, 1″, the pivoting axes 2, 5a and 5b being fixed with respect to the movement of the carriage 7.

[0022] An articulating push and pull rod 9 is provided fixed firstly to the said carriage and secondly to a connecting rod 10 free to pivot about an axis 11 and provided with a roller 12 in order to move the carriage 7, the axis 11 being fixed with respect to axes 5a, 5b about which parts 4a, 4b pivot.

[0023] The roller 12 cooperates with a cam 13 shown partially in FIGS. 3 and 4.

[0024] Depending on the position of the roller 12 on the cam 13, it can be seen that the mould may be open (FIG. 3) or closed (FIG. 4), since the roller follows the path shown in 14 in FIGS. 3 and 4.

[0025] The roller 12 and the cam 13 must have a relative movement with respect to each other. For example, the cam 13 moves with respect to the support of mould 1 formed by the axes 5a, 5b and 2 which are then fixed, or more particularly the entire mould and its actuation system move with respect to the cam 13 which is then fixed.

[0026] As shown in particular in FIGS. 2 and 4, in the closed position the longitudinal axes of the connecting rods 3a, 3b are approximately in line with each other along the line between the pivot axes 5a, 5b of the pivoting parts 4a, 4b, or the said axes 5a, 5b are approximately in the same plane as the plane containing the articulation axes of the connecting rods 3a, 3b.

[0027] In this position, the articulation axes of the connecting rods 3a, 3b with the pivoting parts 4a, 4b may be slightly beyond the line connecting the pivot axes 5a, 5b.

[0028] In this way, the mould is held partly locked by the pressure applied by the carriage, but also by the geometry of the system that opposes opening without deliberate backward movement of the carriage 7.

[0029] FIG. 5 shows a set of twelve moulds la to 11 each provided with an actuation system like that described with reference to FIGS. 1 to 4, and for example this assembly being used to blow hollow bodies such as bottles, from thermoplastic preforms.

[0030] Moulds 1a to 11 are arranged as shown in FIG. 5, around a circle at the centre of which there is a common cam 13, in this case fixed.

[0031] The previously described pivot axes references 2, 5a, 5b, and the pivot axes 11 of the connecting rods 10, and obviously also the rails 8a, 8b on which the carriages 7 are free to move, are fixed, for example on a plate not shown that is free to rotate with respect to the cam 13 (although obviously, it would be possible to imagine a mobile cam and fixed moulds).

[0032] The shape of the cam is designed and chosen so that one or several moulds open (1a, 1b) or close (1c to 11) as shown in the said FIG. 5, as a function of the angular position of the cam 13.

Claims

1. Actuation system for a mould (1) in two parts forming two half-moulds (1′,1″) articulated to each other about an axis (2) forming a hinge and controlled between an open position and a closed position through a translation carriage (7) moved in a forward-backward movement, characterized in that each half-mould (1′, 1″) is also articulated on a part (4a, 4b) that pivots around an axis (5a, 5b) and that is moved in rotation by at least one actuation rod (6a, 6b) articulated by its ends to the said pivoting part (4a, 4b) and the said translation carriage (7) respectively.

2. Actuation system according to claim 1, characterized in that each half-mould (1′, 1″) is articulated to the pivoting part (4a, 4b) by means of at least one connecting rod (3a, 3b).

3. Actuation system according to any one of claims 1 and 2, characterized in that the actuation rods (6a, 6b) of the pivoting parts (4a, 4b) of the half-moulds (1′, 1″) are articulated on a common translation carriage (7).

4. Actuation system according to claim 3, characterized in that the translation carriage (7) is composed of a cross piece that is installed free to slide on at least two rails (8a, 8b) and on which the actuation rods (6a, 6b) are articulated.

5. Actuation system according to one of claims 1 to 4, characterized in that the translation carriage (7) is moved forwards-backwards by at least one roller (12) that cooperates with a cam (13).

6. Actuation system according to claim 5, characterized in that the roller (12) is arranged on a rod (10) installed free to pivot about an axis (11) fixed with respect to the pivot axes (5a, 5b) of the pivoting parts (4a, 4b) actuating the half-moulds (1′, 1″).

7. Actuation system according to one of claims 2 to 6, characterized in that in the closed position of the half moulds (1′, 1″), the longitudinal axes of the connecting rods (3a, 3b) installed between the said half-moulds (1′, 1″) and the pivoting parts (4a, 4b) are approximately in line with each other along the line connecting the pivot axes (5a, 5b) of the said pivoting parts (4a, 4b).

8. Set of moulds (1a, 11) each formed of two half-moulds articulated about an axis forming a hinge and each provided with an actuation system according to any one of claims 1 to 7, characterized in that the moulds (1a, 11) are arranged in a circle or along the arc of a circle and in that the translation carriages are moved by rollers that cooperate with a common cam (13), the said mould being moved relative to the cam (13).

9. Set of moulds according to claim 8, characterized in that the moulds (1a, 11) are fixed on an element that rotates about the common cam (13) that is fixed in position.